This invention relates to an atomic absorption spectrophotometer which improves the accuracy of calculation output signals.
In atomic absorption spectrophotometers in general, absorption of light other than by an atom to be analyzed, that is so-called "background absorption", occurs, and hence the accuracy of of signals drops.
Background absorption includes scattering of light by fine particles and absorption of light by molecular gas, for example, and they are factors that cause measurement error of the spectrophotometer. Accordingly, the atomic absorption spectrophotometers are generally equipped with a function of correcting the background absorption.
The atomic absorption spectrophotometers having such a correction function of the background absorption are known, for example, from the magazine "Analytical Chemistry", Vol. 49, No. 8, July, 1977, p.p. 1106-1112.
The conventional systems such as described above involve the problem that the measurement with a high level of accuracy can not be made because the absorbancies due to the background absorption in sample light and reference light are compared with each other at different detection timings so as to detect output signals.